/usr/ is in libnfft3-dev 3.3.2-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/libnfft3-dev/
/usr/include/
/usr/include/nfft3.h
/usr/include/nfft3mp.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/nfft3.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/nfft3f.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/nfft3l.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libnfft3-dev/copyright
/usr/lib/x86_64-linux-gnu/libnfft3.so
/usr/lib/x86_64-linux-gnu/libnfft3_threads.so
/usr/lib/x86_64-linux-gnu/libnfft3f.so
/usr/lib/x86_64-linux-gnu/libnfft3f_threads.so
/usr/lib/x86_64-linux-gnu/libnfft3l.so
/usr/lib/x86_64-linux-gnu/libnfft3l_threads.so
/usr/share/doc/libnfft3-dev/changelog.Debian.gz